1. Field of the Invention
The present invention relates to a hydrodynamic torque converter, comprising a torsional vibration damper arrangement which is arranged in a torque-transmission path between a lockup clutch of the torque converter and a turbine impeller of the torque converter. The torsional vibration damper arrangement has a primary side, which is coupled to the lockup clutch or forms a part thereof, and a secondary side, which is coupled to the turbine impeller and/or forms a part thereof. The primary side and the secondary side are able to rotate with respect to one another about a converter axis of rotation, counter to the action of a damper spring arrangement.
2. Description of the Related Art
When fitting such hydrodynamic torque converters into a drive system, the problem is often encountered that there is a very slight axial offset or a very slight axial inclination between a crankshaft, which is to be connected to a converter casing, and a converter output shaft which is to be connected to the turbine impeller, generally the transmission input shaft. This axial inclination may lead to radial forces being produced in the area of the torsional vibration damper during operation, and these forces, particularly in the area of various bearings, may lead to excessive wear and to components seizing up.
German reference DE 32 48 119 C2 has disclosed a clutch disk in which a torsional vibration damper integrated therein comprises two cover plates and one hub plate between them. One of the cover plates is guided over an inclined surface on the hub, so that a preloading device which is provided is able to automatically center these two damper areas, and imbalance in the clutch disk can be avoided in operation.
The object of the present invention is to provide a hydrodynamic torque converter or a torsional vibration damper therefor with which, by simple structural measures, the problems induced by an axial offset are eliminated.
According to the invention, this object is achieved by means of a hydrodynamic torque converter comprising a torsional vibration damper arrangement which is arranged in a torque-transmnission path between a lockup clutch of the torque converter and a turbine impeller of the torque converter. The torsional vibration damper arrangement has a primary side, which is coupled to the lockup clutch or forms a part thereof, and a secondary side, which is coupled to the turbine impeller and/or forms a part thereof. The primary side and secondary side are able to rotate with respect to one another about a converter axis of rotation, counter to the action of a damper spring arrangement. The turbine impeller has a bearing area for the primary side, which allows radial movement of the primary side with respect to the turbine impeller.
Since, in the torque converter according to the invention, the primary side is mounted on the turbine impeller in such a manner that radial movement between these two components is possible, any axial offset which is present cannot lead to jamming in this bearing area, with the result that the wear is significantly reduced and the risk of seizing up is avoided.
By way of example, it is possible for the bearing area to form a bearing surface which narrows in one direction of the axis of rotation and on which the primary side bears by way of a mating bearing surface.
In this case, the radial movement facility can be obtained in a simple manner if the primary side is preloaded by a preloading arrangement in a direction, with respect to the turbine impeller, in which the bearing surface widens.
By way of example, the preloading arrangement may comprise a preloading spring, preferably a diaphragm spring, which is supported on the turbine impeller, on the one hand, and on the primary side, on the other hand.
The bearing area may, for example, be of frustoconical design or may form a bearing surface with a curved contour.
In order to be able to optimize the bearing area with regard to the particular requirements, i.e. in order for it to be possible to use a material with suitable bearing or sliding properties, it is proposed for the bearing area to be formed by a bearing component arranged on the turbine impeller.
As an alternative, however, in order to obtain a structure which is as simple and inexpensive as possible, it is possible for the bearing area to be formed by a surface section of the turbine impeller.
In the hydrodynamic torque converter according to the invention, the structure may, for example, be such that the secondary side has two covering-disk areas which are arranged at an axial distance from one another and between which there is a central disk element of the primary side. The damper spring arrangement has at least one damper spring which is supported on the covering-disk areas or the central disk element. Furthermore, the central disk element is mounted on the bearing area.
In order to allow the damping characteristic of the torsional vibration damper arrangement in the hydrodynamic torque converter according to the invention to be adapted to different damping requirements, it is proposed for the central disk element rotatably to support at least one flywheel mass, preferably a planet wheel, which flywheel mass is driven in rotation in the event of relative rotation between the primary side and the secondary side.
In this case, it is possible for the at least one flywheel mass to be driven in rotation by the turbine impeller and/or a component which is connected thereto.
The present invention also relates to a torsional vibration damper, in particular for a hydrodynamic torque converter, comprising a primary side, which is or can be connected to a primary component, and a secondary side, which is or can be connected to a secondary component. The primary side and the secondary side are able to rotate with respect to one another about an axis of rotation, counter to the action of a damper spring arrangement. The primary side furthermore is mounted on a bearing area of the secondary component in such a manner that it can be displaced in the radial direction.
A torsional vibration damper of this nature provides a very compact structure, since the primary side is mounted directly on that component which is driven in rotation by the secondary side or is rotatably coupled thereto. Furthermore, the radial movement which is made possible can be used to avoid the occurrence of jamming in this bearing area.
By way of example, it is possible for the bearing area to form a bearing surface which narrows in one direction of the axis of rotation, and for the primary side to be preloaded with respect to the secondary component, by a preloading arrangement, in a direction in which the bearing surface widens.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.